There are 3 types of high end leatherworking, tribal, elemental, and dragonscale. When you get to the 225-250 area of leveling LW you can do quests to get one of the three. Once you choose one, however, you cannot choose another. Its not really a problem to find another LW who can make the stuff of other branches, and since you'll be a skin/LW, you can supply them the mats easily.